The dim ens ion o f them ass concre te is very huge. A fter the concrete is poured, a g reat dea l o f cem ent hea t of hydration is g iven of.f The heat quantity congreg ated in the concrete can not em it eas ily because o f the hug e dim ension and the rap id r ise in the tem pera ture of insidem ass concrete, so the temperature difference between interna l and ex terna l concrete is very g rea t. In the course o f the r ise and drop of the temperature, the temperature stress inside concrete changes greatly because o f the restriction, w hich induces the de le terious crack to com e in to being and the construction of the m ass concrete to be difficu lt. Th is article inco rporates w ith a practice fo rm ass concrete construction o f the ra ft founda tion o f the com prehensive bu ilding in N an jing. The tem perature fie ld of them ass concre te is analyzed and simu lated by the finite e lem ent m ethod before construction, and the construction project and the optim ized m ix ture propo rtion are m ade accord ing of the resu lt. The purpo se of the inform ative construction is ach ieved tha t the tem perature mon itoring places are d isposed and them a inta in pro ject is adjusted at any mom ent according to them on-i tor ing inform ation. The practice proves that the tem pera ture va riety ru le ach ieved by theoretic analysis is about the sam e as testing result, the construction pro ject adopted is safe and cred ib le. The application o f the above techn ique m easures assures the successful construction.